Question

The different steps of recombinant DNA technology are given below randomly. (i) Isolation of the DNA fragments or genes to be cloned (ii) Introduction of the recombinant DNA into a suitable cell (usually E.coli) called a host (transformation) (iii) Multiplication/expression of the introduced gene in the host (iv) Selection of the transformed host cells, and identification of the clone containing the desired gene/DNA fragment (v) Insertion of the isolated gene in a suitable plasmid vector. Which of the following represents the correct sequence of steps?
A) (i),(iii), (ii), (iv), (v)
B) (iii), (ii), (i), (v), (iv)
C) (i), (v), (ii), (iv), (iii)
D) (v), (i), (iii), (iv), (ii)

Answer 1

Recombinant DNA Technology (RDT) is a series of procedures that are used to join two different DNA strands together to form sequences that are not found in the genome. These techniques aid in the production of new genetic combinations that are valuable in the field of biotechnology.

Complete answer:
Recombinant DNA refers to a DNA molecule that is formed after the joining of two different DNA strands and inserted into a host organism to produce new genetic recombination. There are six steps present in RDT. They are as follows:
Isolating genetic material: The DNA molecule is isolated in its pure form from DNA extractions techniques using isopropyl alcohol, etc.
Restriction enzyme digestion: The isolated DNA strand containing the gene of interest and the plasmid to which the DNA strand is to be ligated are both restricted digested with the help of restriction enzymes to create blunt or sticky ends.
DNA amplification using PCR: Copies of DNA molecules are created using a technique called Polymerase Chain Reaction (PCR).
Ligation of DNA molecules: The DNA molecule is then ligated with the vector using DNA ligase.
Inserting the recombinant plasmid into the host cell- The recombinant vector is now inserted into the host cell through a process known as transformation.
Isolation of recombinant cells: After the process of transformation, the host cell is provided with a suitable medium to multiply. Selectable markers are added to differentiate recombinant cells from normal cells.

Hence, the correct option is C.

Note:
Restriction enzymes are a type of specialized enzyme that recognizes specific DNA sequences present on the DNA strand and are digested only in that part of the sequence. These sites are known as restriction sites. These enzymes produce two types of ends in the DNA strand: blunt ends and staggered ends.